In this paper, a new unscented Kalman filter(Unscented Kalman filter, UKF) for nonlinear system with both one-step randomly delayed measurements and colored measurement noises is proposed. Firstly, the first-order Mar...
详细信息
In this paper, a new unscented Kalman filter(Unscented Kalman filter, UKF) for nonlinear system with both one-step randomly delayed measurements and colored measurement noises is proposed. Firstly, the first-order Markov sequence model is used to whiten colored noise, at the same time, an independent and identically distributed Bernoulli variable is used to model the delay of measurement data transmission, then the model of nonlinear one-step randomly time delay system with colored noise whitening is established. Secondly, filter recursion formula of UKF under the above model is proposed through unscented transformation(Unscented transformation, UT) to calculate the posterior mean and covariance of the nonlinear state based on the Bayesian filter framework. The proposed new UKF method can effectively deal with the issue that traditional UKF is failure under the condition of one-step randomly delayed measurements and colored measurement noises. The efficiency and superiority of the proposed method are illustrated in a numerical example for a target tracking problem.
In order to study the cement hydration characteristics in the process of cement condensation, based on eddy current measuring technology and GMR(giant magnetoresistive sensor), it designed a non-contact cement-hydrati...
详细信息
In order to study the cement hydration characteristics in the process of cement condensation, based on eddy current measuring technology and GMR(giant magnetoresistive sensor), it designed a non-contact cement-hydration-characteristics measuring device. As an advanced nondestructive detection technology, Eddy current detection is convenient and *** GMR has high sensitivity and good linearity. Combining eddy current detection technology with GMR in design, it successfully gets rid of electrode polarization in traditional contact testing method, and greatly improves the accuracy of cement impedance measurement, and it effectively solves the collision problem that the excitation coil needs high frequency and the measure must have high sensitivity. The measuring device mainly includes magnetic field, GMR sensor, and STM32 F427 micro-computer data acquisition system. The testing results show that the device has high precision, good repeatability.
In the process of geological exploration, the development of automatic control is insufficient. The paper presents an improved strategy of attitude control for directional drilling tools used in the geological environ...
详细信息
In the process of geological exploration, the development of automatic control is insufficient. The paper presents an improved strategy of attitude control for directional drilling tools used in the geological environment. The drilling kinematics model is linearized with the Taylor series, and the model linearization solves the nonlinear term of the azimuth *** PI controllers are used to control attitude inclination and azimuth, respectively. The results of the transient simulation are presented, and the control effect of improved performance are certificated.
The traditional wired seismograph has disadvantages such as cumbersome cable, complicated wiring, crosstalk and noise between adjacent transmission lines. In addition, the dynamic range of the instrument is small, and...
详细信息
The traditional wired seismograph has disadvantages such as cumbersome cable, complicated wiring, crosstalk and noise between adjacent transmission lines. In addition, the dynamic range of the instrument is small, and the observation of seismic signals is not intuitive, which can not meet the needs of high-precision seismic exploration. In order to solve these problems, the design of distributed three component seismic data acquisition system based on Lo Ra wireless communication technology is proposed. The system uses Lo Ra long-distance wireless communication technology and 24 bit Σ-Δ ADC, which realizes long-distance wireless communication and large dynamic range seismic data acquisition. Besides, the system has manmachine interaction interface, which can observe the parameters of seismic waveform in real time and adjust sampling rate directly. The whole circuit has the advantages of simple design, high precision and good stability. To sum up, the design has certain practical value and application prospect.
The residual vibration(RV) problem of the flexible link manipulators(FLMs) is very difficult to solve due to the low stiffness and the underactuated feature of these *** paper presents a control strategy with zero...
详细信息
The residual vibration(RV) problem of the flexible link manipulators(FLMs) is very difficult to solve due to the low stiffness and the underactuated feature of these *** paper presents a control strategy with zero RV for a planar singlelink flexible manipulator(PSLFM).The stable control objective of the system is to stabilize the PSLFM at a target equilibrium point with zero ***,the dynamic model of the PSLFM is built by using the assumed mode method(AMM).Then,we transform the control to the trajectory tracking control.A forward trajectory and a reverse trajectory are obtained by using a bidirectional trajectories planning ***,these two trajectories are connected by using the genetic algorithm(GA).After doing this,we get a trajectory of the system from the initial equilibrium point to the target equilibrium ***,we design a trajectory tracking controller based on the sliding mode variable structure control method to control the PSLFM track this *** simulation results show that the PSLFM arrives the target equilibrium point with zero RV,which demonstrates the effectiveness of this control strategy.
Overhauser magnetometer is a weak magnetic measuring instrument based on the dynamic nuclear polarization of free radical *** has the characteristics of high precision,high sensitivity,low power consumption and contin...
详细信息
Overhauser magnetometer is a weak magnetic measuring instrument based on the dynamic nuclear polarization of free radical *** has the characteristics of high precision,high sensitivity,low power consumption and continuous *** is widely used in geophysics,aeromagnetic surveying,satellite Magnetic measuring,military and various engineering *** at the problem that the measurement accuracy of the magnetometer prototype is low and the measurement effect is poor when the angle between the probe axis and the geomagnetic field is 0°,several optimization methods are proposed and the magnetometer is optimized by adding the frequency measurement channel on the basis of the *** on the standard deviation of GSM-19 measurement data,comparing the experimental data that use the multi-channel frequency measurement algorithm,the standard deviation of prototype data decreases from 0.397 to 0.203 when the angle between probe axial and geomagnetic field is 45°,the standard deviation of the prototype data decreases from 0.631 to 0.371 when the angle between probe axial and geomagnetic field is 0°,which provides an important reference for the follow-up optimization of the magnetometer.
Remote sensing hyperspectral imaging can obtain rich spectral information of terrestrial objects, which allows the indistinguishable matter in the traditional wideband remote sensing to be distinguished in hyperspectr...
详细信息
Remote sensing hyperspectral imaging can obtain rich spectral information of terrestrial objects, which allows the indistinguishable matter in the traditional wideband remote sensing to be distinguished in hyperspectral remote *** image has the characteristics of "combining image with spectrum". Making full use of spectral information and spatial information in hyperspectral image is the premise of obtaining accurate classification results. At present, most of hyperspectral data feature extraction algorithms mainly utilize local spatial information in the same channel and spectral information in the same spatial location of different channels. However, these methods require a large amount of prior knowledge, it is difficult to fully grasp the hyperspectral data of all spatial and spectral information, and the model generalization ability is poor. With the development of deep learning, convolutional neural network shows superior performance in all kinds of visual tasks, especially in the two-dimensional image classification, and could get a high classification accuracy. In this paper, an image classification method based on three-dimensional convolution neural network is proposed based on the structural properties of hyperspectral data. In the proposed method, first the stereo image blocks of hyperspectral data are intercepted, then multi-layer convolution and pooling operation of extracted blocks by convolutional neural network are implemented to obtain the essential information of hyperspectral data, finally the classification of hyperspectral data is completed. The experimental results show the proposed method could provide better feature expression and classification accuracy for hyperspectral image.
With the application of magnetic thin films becoming more and more widespread,people pay more and more attention to the performance *** order to obtain a magnetic film with a specific performance,it is very important ...
详细信息
With the application of magnetic thin films becoming more and more widespread,people pay more and more attention to the performance *** order to obtain a magnetic film with a specific performance,it is very important to judge the quality of the magnetic film and measure the magnetic properties of the ***,with the increase of the film preparation process,the thickness of the prepared film is getting thinner and the magnetic moment signal contained therein is also *** brings a certain degree of difficulty to the traditional measurement *** example,the VSM system that obtains the hysteresis loop by measuring the magnetic moment signal has become somewhat inadequate for the measurement of ultra-thin *** order to solve this issue,a new method based on anomalous Hall effect is introduced in this *** test system of this system adopts the four-probe measuring method,a constant current is applied across the surface of the film sample,and the abnormal Hall voltage is measured at the other two *** R-H curve of the sample can be obtained through *** compared to VSM measurement,this method is simpler and stable,more accurate,which can greatly reduce the anomalous Hall-effect device R-H characteristic measurement cost.
Based on the hierarchical control system of sintering process, a carbon efficiency performance assessment method is proposed. Firstly, performance evaluation model of sintering process is designed according to the cha...
详细信息
Based on the hierarchical control system of sintering process, a carbon efficiency performance assessment method is proposed. Firstly, performance evaluation model of sintering process is designed according to the characteristics hierarchical control structure of sintering process. Then, the performance index of the comprehensive coke ratio(CCR) in the carbon efficiency optimization layer is designed to achieve the carbon efficiency performance assessment. Next, the performance indexes of burning through point(BTP) control system of the optimization control layer and the fuzzy synthetic evaluation method based on information entropy are designed. The proposed carbon efficiency performance assessment method is implemented on the simulation platform of the sintering process in the laboratory, which effectively realized the performance assessment for sintering process plant level control system, and then provides effective information for the staff to maintain the control system.
This paper focuses on the scheme of cooperative lane change motion planning of multiple connected and automated vehicles, so as to minimize the time for lane change while penalizing large steering angles subject to ha...
详细信息
暂无评论